Institute for Complex Molecular Systems and Molecular Materials and Nanosystems, Eindhoven University of Technology, Eindhoven, Netherlands.
Department of Chemistry, Indian Institute of Technology (IIT) Bombay, Mumbai, India.
Chirality. 2023 Mar;35(3):147-154. doi: 10.1002/chir.23527. Epub 2023 Jan 13.
When irradiating a molecular material containing photo-isomerizable groups with pure circularly polarized light, a particular handedness may get imprinted into the material. To study the mechanism and kinetics of this process in situ and operando, we have developed a new chiroptical tool where the circular polarization of the incident circularly polarized light is monitored after transmission through the photoactive layer. Practical limits to the resolution and sensitivity of the measurements as well as its calibration are discussed. To aid interpretation of experimental results, we present kinetic Monte Carlo simulations on a model for the active material involving photo-induced reorientation of molecules in a cholesteric organization. The simulations support the interpretation of a transient minimum in the degree of circular polarization of the transmitted light in terms of a nematic transient state during photo-inversion of a cholesteric organization in the molecular material.
当用纯圆偏振光辐照含有光致变色基团的分子材料时，材料中可能会被记录下特定的手性。为了在原位和实时条件下研究该过程的机制和动力学，我们开发了一种新的手性工具，其中监测入射圆偏振光的圆偏振度在穿过光活性层后发生的变化。本文讨论了测量的分辨率和灵敏度的实际限制及其校准。为了帮助解释实验结果，我们对涉及分子在胆甾相组织中光诱导重取向的活性材料的模型进行了动力学蒙特卡罗模拟。模拟结果支持了用瞬态向列相来解释透过光的圆二色性的瞬态最小值，该瞬态向列相是在分子材料的胆甾相组织光反转过程中产生的。
